Class: PacketGen::PcapNG::Block Abstract

Inherits:
BinStruct::Struct
  • Object
show all
Defined in:
lib/packetgen/pcapng/block.rb

Overview

This class is abstract.

Base class for all block types

Author:

  • Sylvain Daubert

  • LemonTree55

Direct Known Subclasses

EPB, IDB, SHB, SPB, UnknownBlock

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ Block

Returns a new instance of Block.



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# File 'lib/packetgen/pcapng/block.rb', line 31

def initialize(options={})
  super
  endianness(options[:endian] || :little)
  recalc_block_len
end

Instance Attribute Details

#block_len ⇒ Integer

32-bit block length

Returns:



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# File 'lib/packetgen/pcapng/block.rb', line 25

define_attr :block_len, BinStruct::Int32

#block_len2 ⇒ Integer

32-bit block length

Returns:



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# File 'lib/packetgen/pcapng/block.rb', line 29

define_attr :block_len2, BinStruct::Int32

#endian ⇒ :little, :big

Returns:



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# File 'lib/packetgen/pcapng/block.rb', line 16

def endian
  @endian
end

#type ⇒ Integer

32-bit block type

Returns:



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# File 'lib/packetgen/pcapng/block.rb', line 21

define_attr :type, BinStruct::Int32

Instance Method Details

#options? ⇒ Boolean

Has this block option?

Since:

  • 2.7.0

Returns:



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# File 'lib/packetgen/pcapng/block.rb', line 40

def options?
  @attributes.key?(:options) && @attributes[:options].sz.positive?
end

#pad_field(*fields) ⇒ void

This method returns an undefined value.

Pad given field to 32 bit boundary, if needed

Author:

  • LemonTree55

Parameters:

  • fields to pad



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# File 'lib/packetgen/pcapng/block.rb', line 55

def pad_field(*fields)
  fields.each do |field|
    obj = @attributes[field]
    obj << "\x00" * -(obj.sz % -4)
  end
end

#recalc_block_len ⇒ void

This method returns an undefined value.

Calculate block length and update block_len and block_len2 fields



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# File 'lib/packetgen/pcapng/block.rb', line 46

def recalc_block_len
  len = attributes.map { |f| @attributes[f].to_s }.join.size
  self.block_len = self.block_len2 = len
end